At the 1912 Summer Olympics in Stockholm, something rather unusual happened with the medals awarded in the men's pole vault competition. Ordinarily when there is a tie for second place, multiple silver medals are awarded and no bronze medals. However, at this event six medals were awarded: one gold, two silver, and three bronze. I believe this is the only time there was a deviation from the standard practice.
Some sports (Judo, Wrestling, etc.) regularly award multiple bronze medals, but for different reasons. Those sports are head-to-head and use a playoff style bracket for determining medal winners, and there can't otherwise be a tie. There can't be two gold medalists in a single boxing event, for example. And if there were some way for two boxers to tie in the gold medal match, presumably they would each be awarded a gold medal and no one would receive a silver. The regular awarding of two bronze medals does not deviated from the standard practice because those two competitors have essentially tied.
The standard practice is you only get a gold if you were first, you only get a silver if you were beaten by just one person, and you only get a bronze if you were beaten by just two people.
I'm not considering instances where medals were awarded well after the event, e.g. Jim Thorpe.
At the 1908 Olympics, the men's pole vault also had a few ties. They awarded two gold and three bronze medals, only. They did not give the latter group silver medals and then award a bronze to a subsequent finisher. 1980 was the next tie in pole vault, and they awarded one gold, two silver, and no bronze. I can find no other instance where a silver medal was awarded to a competitor who was beaten by more than one person, nor where a bronze medal was given to someone who was beaten by more than two competitors.
I have found a few sources discussing what happened at the pole vault event in 1912, with some even commenting that it was unusual, but I cannot find anything explaining why this was done. What was the reason for awarding the bronze medals in this instance? It seems to be a unique deviation.